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Articles 1381 - 1410 of 2584

Full-Text Articles in Engineering

Roll-To-Roll Synthesis Of Vertically Aligned Carbon Nanotubes For Electrical Double Layer Capacitors, Margarita R. Arcila-Velez, Jingyi Zhu, Anthony Childress, Mehmet Karakaya, Ramakrishna Podila, Apparao M. Rao, Mark E. Roberts Apr 2014

Roll-To-Roll Synthesis Of Vertically Aligned Carbon Nanotubes For Electrical Double Layer Capacitors, Margarita R. Arcila-Velez, Jingyi Zhu, Anthony Childress, Mehmet Karakaya, Ramakrishna Podila, Apparao M. Rao, Mark E. Roberts

Graduate Research and Discovery Symposium (GRADS)

No abstract provided.


Effect Of Surface Parameters On Interfacial Water Film Behavior, Brittany Glatz, Luke Rhym, Sapna Sarupria Apr 2014

Effect Of Surface Parameters On Interfacial Water Film Behavior, Brittany Glatz, Luke Rhym, Sapna Sarupria

Graduate Research and Discovery Symposium (GRADS)

Vapor-to-liquid and liquid-to-solid transitions on mineral surfaces are the primary pathways for phase transitions in atmospheric water. These phase transitions affect the microphysics of clouds and have significant effects on the weather and climate. Our overall goal is to elucidate the mechanisms through which surfaces affect these transitions, and develop predictive abilities to correlate surface properties to the thermodynamics and kinetics of the phase transitions. In this work, we use molecular dynamics simulations to study the structure, and dynamics of water near kaolinite-like surfaces. Kaolinite is the most abundant mineral dust in the atmosphere. We specifically investigate the effect of …


Carbon Fibers Derived From Pan/Bio-Based Bicomponent Precursor, Jing Jin Apr 2014

Carbon Fibers Derived From Pan/Bio-Based Bicomponent Precursor, Jing Jin

Graduate Research and Discovery Symposium (GRADS)

No abstract provided.


Optimization Of Pyrochlore Catalysts For Dry Reforming Of Methane, Felipe Polo-Garzon, Ming He, David A. Bruce Apr 2014

Optimization Of Pyrochlore Catalysts For Dry Reforming Of Methane, Felipe Polo-Garzon, Ming He, David A. Bruce

Graduate Research and Discovery Symposium (GRADS)

No abstract provided.


Comparative Analysis Of Requirements Change Prediction Models: Manual, Linguistic, And Neural Network, Beshoy Markos, James L. Mathieson, Joshua D. Summers Apr 2014

Comparative Analysis Of Requirements Change Prediction Models: Manual, Linguistic, And Neural Network, Beshoy Markos, James L. Mathieson, Joshua D. Summers

All CEDAR Publications

Requirement change propagation, if not managed, may lead to monetary losses or project failure. The a posteriori tracking of requirement dependencies is a well-established practice in project and change management. The identification of these dependencies often requires manual input by one or more individuals with intimate knowledge of the project. Moreover, the definition of these dependencies that help to predict requirement change is not currently found in the literature. This paper presents two industry case studies of predicting system requirement change propagation through three approaches: manually, linguistically, and bag-of-words. Dependencies are manually and automatically developed between requirements from textual data …


Fabrication And Analysis Of Soy Flour Filled Polyethylene Fibers, Ozgun Ozdemir, Sam Lukubira, Amod Ogale, Paul Dawson Apr 2014

Fabrication And Analysis Of Soy Flour Filled Polyethylene Fibers, Ozgun Ozdemir, Sam Lukubira, Amod Ogale, Paul Dawson

Graduate Research and Discovery Symposium (GRADS)

Fibers composed of soy flour (soy) and linear low density polyethylene (PE) were produced by melt spinning method. The mixing time of soy flour and PE was adjusted to get better dispersion of soy flour inside the matrix. The inclusion of soy decreased tensile modulus by 35% and tensile strength by 30% of the fibers compared with 950 MPa and 43 MPa, respectively, for PE fibers. Strain to failure for soy-PE fibers was 292% where PE fibers have strain to failure at 513%. Tensile properties of soy-PE fibers are comparable to those of pure PE. Even washing did not deteriorated …


Integrating Algaculture Into Small Wastewater Treatment Plants: Process Flow Options And Life Cycle Impacts, Muriel M. Steele, Annick Anctil, David A. Ladner Apr 2014

Integrating Algaculture Into Small Wastewater Treatment Plants: Process Flow Options And Life Cycle Impacts, Muriel M. Steele, Annick Anctil, David A. Ladner

Publications

Algaculture has the potential to be a sustainable option for nutrient removal at wastewater treatment plants. The purpose of this study was to compare the environmental impacts of three likely algaculture integration strategies to a conventional nutrient removal strategy. Process modeling was used to determine life cycle inventory data and a comparative life cycle assessment was used to determine environmental impacts. Treatment scenarios included a base case treatment plant without nutrient removal, a plant with conventional nutrient removal, and three other cases with algal unit processes placed at the head of the plant, in a side stream, and at the …


2014 Chemical And Biomolecular Graduate Research Symposium Program, Clemson University Mar 2014

2014 Chemical And Biomolecular Graduate Research Symposium Program, Clemson University

Chemical and Biomolecular Graduate Research Symposium

Program for the 2014 Graduate Research Symposium in Holmes Ballroom - Clemson House.


Comparison Of Graph Generation Methods For Structural Complexity Based Assembly Time Estimation, Essam Z. Namouz, Joshua D. Summers Feb 2014

Comparison Of Graph Generation Methods For Structural Complexity Based Assembly Time Estimation, Essam Z. Namouz, Joshua D. Summers

All CEDAR Publications

This paper compares two different methods of graph generation for input into the complexity connectivity method to estimate the assembly time of a product. The complexity connectivity method builds predictive models for assembly time based on 29 complexity metrics applied to the product graphs. Previously, the part connection graph was manually created, but recently the assembly mate method and the interference detection method have introduced new automated tools for creating the part connectivity graphs. These graph generation methods are compared on their ability to predict the assembly time of multiple products. For this research, eleven consumers products are used to …


A Comparative Survey Of Domestic And International Experiences In Capstone Design, Beshoy Morkos, Joshua D. Summers, Samantha Thoe Jan 2014

A Comparative Survey Of Domestic And International Experiences In Capstone Design, Beshoy Morkos, Joshua D. Summers, Samantha Thoe

All CEDAR Publications

This paper studies the differences between student experiences in domestic and international capstone design offerings for mechanical engineering students at Clemson University. For this, we conducted surveys and interviews of students participating in both the traditional domestic version of a capstone course at Clemson University and a group of students that participated in an international, study abroad version of a capstone course jointly administered by Clemson University and West Virginia University. The surveys were given to students before and after the program to assess whether the international component had an impact on their global awareness when compared to their peers …


Assembly Time Estimation: Assembly Mate Based Structural Complexity Metric Predictive Modeling, Joseph E. Owensby, Joshua D. Summers Jan 2014

Assembly Time Estimation: Assembly Mate Based Structural Complexity Metric Predictive Modeling, Joseph E. Owensby, Joshua D. Summers

All CEDAR Publications

This paper presents an automated tool for estimating assembly times of products based on a three step process: connectivity graph generation from assembly mate information, structural complexity metric analysis of the graph, and application of the complexity metric vector to predictive artificial neural network models. The tool has been evaluated against different training set cases, suggesting that partially defined assembly models and training product variety are critical characteristics. Moreover, the tool is shown to be robust and insensitive to different modeling engineers. The tool has been implemented in a commercial CAD system and shown to yield results of within ±25% …


Development Of A Geometric Model Retrieval System: A Design Exemplar Case Study, Murty Srirangam, Srinivasan Anandan, Joshua D. Summers Jan 2014

Development Of A Geometric Model Retrieval System: A Design Exemplar Case Study, Murty Srirangam, Srinivasan Anandan, Joshua D. Summers

All CEDAR Publications

This paper presents a case study examining design exemplar technology implemented as a search and retrieval tool for tyre mould inserts. Limitations of using the geometric-based exemplar approach, such as tediousness of authoring exemplars and time complexity, are identified and addressed through a new parametric-based exemplar approach. Here, the maxima and minima are calculated based upon the specifications of the query mould insert. The design exemplar is demonstrated to be useful primarily in prototyping query mechanisms. Ultimately, customer requirements necessitated implementing the parametric approach as a dedicated software package grounded on the exemplar-based prototyped query mechanism.


Manufacturing Assembly Time Estimation Using Structural Complexity Metric Trained Artificial Neural Networks, Michael G. Miller, James L. Mathieson, Joshua D. Summers, Gregory M. Mocko Jan 2014

Manufacturing Assembly Time Estimation Using Structural Complexity Metric Trained Artificial Neural Networks, Michael G. Miller, James L. Mathieson, Joshua D. Summers, Gregory M. Mocko

All CEDAR Publications

Assembly time estimation is traditionally a time-intensive manual process that requires detailed geometric and process information, which is often subjective and qualitative in nature. As a result, assembly time estimation is rarely applied during early design iterations. In this paper, the authors explore the possibility of automating the assembly time estimation process while reducing the level of design detail required. In this approach, they train artificial neural networks (ANNs) to estimate the assembly times of vehicle subassemblies using either assembly connectivity or liaison graph properties, respectively, as input data. The effectiveness of estimation is evaluated based on the distribution of …


Mechanistic Characterization Of Rubberized Asphalt Mixture And Design Using Full Scale Tire-Pavement Finite Element Modeling, Sajib Saha Dec 2013

Mechanistic Characterization Of Rubberized Asphalt Mixture And Design Using Full Scale Tire-Pavement Finite Element Modeling, Sajib Saha

All Theses

Rubberized half-warm mix asphalt (HWMA) is being considered as one of the promising and sustainable solutions to the current environmental and economic crisis of asphalt industry. A fully mechanistic characterization and performance analysis of this mixture subjected to realistic loading and temperature conditions is necessary before its application in a practical pavement structure. The objective of this research is to characterize the viscoelastic properties of rubberized HWMA at different temperatures and to develop and validate a finite element model of a tire-pavement structure. In this research, a generalized Maxwell model is chosen to represent the time dependent stress-strain behavior of …


Phonon Transport Analysis Of Semiconductor Nanocomposites Using Monte Carlo Simulations, Mayank Malladi Dec 2013

Phonon Transport Analysis Of Semiconductor Nanocomposites Using Monte Carlo Simulations, Mayank Malladi

All Theses

Nanocomposites are composite materials which incorporate nanosized particles, platelets or fibers. The addition of nanosized phases into the bulk matrix can lead to significantly different material properties compared to their macrocomposite counterparts. For nanocomposites, thermal conductivity is one of the most important physical properties. Manipulation and control of thermal conductivity in nanocomposites have impacted a variety of applications. In particular, it has been shown that the phonon thermal conductivity can be reduced significantly in nanocomposites due to the increase in phonon interface scattering while the electrical conductivity can be maintained. This extraordinary property of nanocomposites has been used to enhance …


Sociallink: A Social Network Based Trust System For P2p File Sharing Systems, Fang Qi Dec 2013

Sociallink: A Social Network Based Trust System For P2p File Sharing Systems, Fang Qi

All Theses

In peer-to-peer (P2P) file sharing systems, many autonomous peers without preexisting trust relationships share files with each other. Due to their open environment and distributed structure, these systems are vulnerable to the significant impact from selfish and misbehaving nodes. Free-riding, whitewash, collusion and Sybil attacks are common and serious threats, which severely harm non-malicious users and degrade the system performance. Many trust systems were proposed for P2P file sharing systems to encourage cooperative behaviors and punish non-cooperative behaviors. However, querying reputation values usually generates latency and overhead for every user. To address this problem, a social network based trust system …


Application Of Image Processing And Finite Element Analysis In Modeling Chloride Diffusion In Concrete, Arash Razmjoo Dec 2013

Application Of Image Processing And Finite Element Analysis In Modeling Chloride Diffusion In Concrete, Arash Razmjoo

All Dissertations

Utilizing numerical simulation models to predict the long-term mechanical and transport behavior of concrete structures is becoming increasingly popular. The majority of these models have been developed using laboratory test data that consider concrete as a homogeneous material with spherical aggregates. These models could not be a represented of real concrete because it has no primitive shaped aggregate besides that the porosity size and distribution varies from point to point. In this study a novel method for more accurate prediction of the chloride diffusion in concrete was developed. A general framework of the quantitative computed tomography (QCT) and finite element …


Development And Verification Of A Test System To Quantify Strain Of An Optical Displacement Indicator And The Design Of A Strain Indicating Prototype, Josh Lake Dec 2013

Development And Verification Of A Test System To Quantify Strain Of An Optical Displacement Indicator And The Design Of A Strain Indicating Prototype, Josh Lake

All Theses

The organic-rich Middle Devonian Marcellus Shale of the Appalachian basin is a rapidly developing natural gas play. Stratigraphic boundaries of the Marcellus Shale in Westmoreland County, Pennsylvania were identified using geophysical logs from 10 vertical gas-producing wells in a 23 sq. km area. Gamma-ray, bulk density, and resistivity well logs were examined to assess hydrocarbon potential. Values of porosity, total organic carbon (TOC), and water saturation (SW) were derived and mapped by incorporating well-log data into Marcellus-specific formulas. Gamma-ray, penetration (minutes per foot drilled), and mud-logging gas (total gas) from 12 horizontal wells from within the study area were also …


A Probabilistic Analysis Of Islanding Effects In A Modeled Distribution System With Renewable Resources, Paul Gooding Dec 2013

A Probabilistic Analysis Of Islanding Effects In A Modeled Distribution System With Renewable Resources, Paul Gooding

All Theses

For this research, an investigation was undertaken regarding the inclusion of renewable resources into the distribution system. This incorporated the increasing prevalence of solar and wind resources, as well as the development of islanding capabilities within distribution systems.


Cost And Embodied Energy Optimization Of Rectangular Reinforced Concrete Beams, Alexander Kosloski Dec 2013

Cost And Embodied Energy Optimization Of Rectangular Reinforced Concrete Beams, Alexander Kosloski

All Theses

Concrete has a large environmental footprint so it is desirable to find ways to efficiently design structural members. Engineers can exercise their abilities early on in the design phase of construction projects to reduce the environmental footprint by minimizing the amount of materials required. One way to achieve these results is to optimize the design of structural concrete. In this study, simple-span rectangular reinforced concrete (RC) beams with a range of different bending moments were analyzed. The primary goal was to combine life cycle analysis (LCA), numerical optimization, and reinforced concrete mechanics to create a framework for designing efficient RC …


Design Of An Optical Position Sensor For Microfiber Actuators, Luxi Cheng Dec 2013

Design Of An Optical Position Sensor For Microfiber Actuators, Luxi Cheng

All Theses

This thesis introduces a new type of sensor that detects the position information of a paramagnetic microfiber and transforms it to computational electrical signal. The original purpose of the sensor is to solve the problem of feedback signal detection of the microfiber control system, which is the problem of detecting the position information for the microfiber. The microfiber will be presented as the experimental object of this sensor to test its capability. A novel optical based approach is used to transfer the position signal to a computer scrutable signal for further analysis.

The purpose of the sensor design comes from …


Speech Enhancement By Exploiting The Baseband Phase Structure Of Voiced Speech For Effective Non-Stationary Noise Estimation, Sanjay Patil Dec 2013

Speech Enhancement By Exploiting The Baseband Phase Structure Of Voiced Speech For Effective Non-Stationary Noise Estimation, Sanjay Patil

All Theses

Speech enhancement is one of the most important and challenging issues in the speech communication and signal processing field. It aims to minimize the effect of additive noise on the quality and intelligibility of the speech signal. Speech quality is the measure of noise remaining after the processing on the speech signal and of how pleasant the resulting speech sounds, while intelligibility refers to the accuracy of understanding speech. Speech enhancement algorithms are designed to remove the additive noise with minimum speech distortion.The task of speech enhancement is challenging due to lack of knowledge about the corrupting noise. Hence, the …


Interstitial Cell Seeding And Dynamic Conditioning Of Aortic Heart Valve Scaffolds, Allison Kennamer Dec 2013

Interstitial Cell Seeding And Dynamic Conditioning Of Aortic Heart Valve Scaffolds, Allison Kennamer

All Theses

In 2011, U.S. Markets for Heart Valve Repair and Replacement Products estimated that roughly four million people in the United States are diagnosed with a heart valve disorder annually. And in the following year, the American Heart Association reported that approximately 35,000 deaths in the US were either directly or indirectly attributed to heart valve disease. Diseases of the heart valve are degenerative in nature and therefore progressively worsen unbeknownst to the patient until symptoms become clinically relevant. By this time, the valve is in such poor condition that complete replacement is often the only effective treatment. Current solutions are …


Development And Testing Of An Impact Plate Yield Monitor For Peanuts, Jacob Fravel Dec 2013

Development And Testing Of An Impact Plate Yield Monitor For Peanuts, Jacob Fravel

All Theses

Advancements in precision agriculture technologies such as yield monitors have allowed for improved management capabilities and reduced input costs for a number of crops. Most commercialized developments in yield monitoring systems and technologies to date have been directed for use with the major grain crops such as corn, soybeans and cereal grains. This research focuses on development and testing of an impact plate yield monitor system for the peanut harvest. Using a four row peanut combine in virginia type peanuts, 4.8 ha (12 ac) of simultaneous yield data were recorded from an Ag Leader® grain (impact plate) yield monitor and …


Chemical, Physical, And Moisture Release Characteristics Of Compost Based Potting Media, Tianzhen Wang Dec 2013

Chemical, Physical, And Moisture Release Characteristics Of Compost Based Potting Media, Tianzhen Wang

All Theses

A commercially available composted cow manure was used as a potting media amendment. A common base mix for woody ornamentals of 8 parts pine bark and 1 part sand was compared with 3 other mixes that contained 20%, 30%, and 40% compost (v/v). The remaining fraction of these three mixes was the base mix (bark and sand). Samples of the pine bark and compost were analyzed to determine the following plant nutrients and mineral concentrations: nitrogen (organic and soluble), carbon, P2O5, K2O, Ca, S, Mg, Mn, Cu, Zn, Na, Fe, and Al.


Synthesis And Characterization Of Multi-Component Enrichment Polymer Layers For Chemical Sensor Applications, James Giammarco Dec 2013

Synthesis And Characterization Of Multi-Component Enrichment Polymer Layers For Chemical Sensor Applications, James Giammarco

All Dissertations

This dissertation presents the building and study of a "universal" enrichment polymer layer system (EPLS). Thin polymer films have been utilized as enrichment layers for evanescent waveguide chemical sensors. The chemical nature of the polymer provides affinity which promotes the analyte to be absorbed. Having one highly sensitive polymer layer is suitable for a single target volatile organic compound (VOC). Here, the development of multi-layered and multi-component thin polymer films has been done to allow for more diverse affinity. Several parameters were identified to make the EPLSs suitable as enrichment layers for chemical sensor devices. The evanescent sensor devices used …


Offshore Wind Energy Study And Its Impact On South Carolina Transmission System, Tingting Wang Dec 2013

Offshore Wind Energy Study And Its Impact On South Carolina Transmission System, Tingting Wang

All Dissertations

As one of the renewable resources, wind energy is developing dramatically in last ten years. Offshore wind energy, with more stable speed and less environmental impact than onshore wind, will be the direction of large scale wind industry. Large scale wind farm penetration affects power system operation, planning and control. Studies concerning type III turbine based wind farm integration problems such as wind intermittency, harmonics, low voltage ride through capability have made great progress. However, there are few investigations concerning switching transient impacts of large scale type III turbine based offshore wind farm in transmission systems. This topic will gain …


Large Scale 3d Mapping Of Indoor Environments Using A Handheld Rgbd Camera, Brian Peasley Dec 2013

Large Scale 3d Mapping Of Indoor Environments Using A Handheld Rgbd Camera, Brian Peasley

All Dissertations

The goal of this research is to investigate the problem of reconstructing a 3D representation of an environment, of arbitrary size, using a handheld color and depth (RGBD) sensor. The focus of this dissertation is to examine four of the underlying subproblems to this system: camera tracking, loop closure, data storage, and integration. First, a system for 3D reconstruction of large indoor planar environments with data captured from an RGBD sensor mounted on a mobile robotic platform is presented. An algorithm for constructing nearly drift-free 3D occupancy grids of large indoor environments in an online manner is also presented. This …


Sulfonated Perfluorocyclobutyl (Pfcb) Aryl Ether Polymers: Synthesis, Reactivity, And Characterization For Polymer Electrolyte Applications, Jiyoung Park Dec 2013

Sulfonated Perfluorocyclobutyl (Pfcb) Aryl Ether Polymers: Synthesis, Reactivity, And Characterization For Polymer Electrolyte Applications, Jiyoung Park

All Dissertations

Perfluorocyclobutyl (PFCB) aryl ether copolymers are excellent candidates for proton exchange membrane (PEM) component in PEM fuel cells. Sulfonated PFCB copolymer membranes exhibit not only high chemical/thermal/mechanical stability but also high proton conductivity. In this regard, PFCB aryl ether copolymers were synthesized via thermal step-growth [2 + 2] cyclopolymerization from aryl bis-(trifluorovinyl ether) (TFVE) monomers and oligomers. Experimental and computational studies confirmed that copolymerization of relatively electron-rich and electron-poor TFVE monomers gave selective-segmented copolymers in an one-pot polymerization. After sulfonation, the PFCB copolymers comprising hydrophilic and hydrophobic segments gave membranes with high proton conductivity. Cross-linked membranes of the sulfonated PFCB …


Characteristics And Contributing Factors Of Emergency Vehicle Crashes, Naji Abdelwanis Dec 2013

Characteristics And Contributing Factors Of Emergency Vehicle Crashes, Naji Abdelwanis

All Dissertations

The purpose of this study is to determine the contributing factors and characteristics associated with emergency vehicle(EV) crashes in order to generate insights about the emergency crashes. This dissertation consists of three approaches to address the purpose. In the first analysis a binary logistic regression model was used to identify the critical factors associated with EV crashes that resulted in fatality compared to those that did not. In the second analysis, an ordered regression model was used to identify critical factors that contributed to the severity of injuries that EV occupants experience in crashes as well as the effect of …